Rustc internal panic with feature(let_chains)

[JakkuSakura]

I tried this code:

#![feature(let_chains)]
<with a lot of code>

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rustc --version --verbose:

rustc 1.52.0-nightly (e9920ef77 2021-02-11)
binary: rustc
commit-hash: e9920ef7749d11fc71cc32ca4ba055bcfeaab945
commit-date: 2021-02-11
host: x86_64-unknown-linux-gnu
release: 1.52.0-nightly
LLVM version: 11.0.1

thread 'rustc' panicked at 'expected `NodeId` to be lowered already for res Local(
    NodeId(48000),
)', compiler/rustc_ast_lowering/src/lib.rs:714:17
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e9920ef7749d11fc71cc32ca4ba055bcfeaab945/library/std/src/panicking.rs:493:5
   1: std::panicking::begin_panic_fmt
             at /rustc/e9920ef7749d11fc71cc32ca4ba055bcfeaab945/library/std/src/panicking.rs:435:5
   2: rustc_ast_lowering::LoweringContext::lower_node_id_generic
   3: rustc_ast_lowering::path::<impl rustc_ast_lowering::LoweringContext>::lower_qpath
   4: rustc_data_structures::stack::ensure_sufficient_stack
   5: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
   6: rustc_ast_lowering::expr::<impl rustc_ast_lowering::LoweringContext>::lower_exprs
   7: rustc_data_structures::stack::ensure_sufficient_stack
   8: rustc_ast_lowering::LoweringContext::lower_stmt
   9: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
  10: <core::iter::adapters::flatten::Flatten<I> as core::iter::traits::iterator::Iterator>::next
  11: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
  12: rustc_arena::cold_path
  13: rustc_ast_lowering::expr::<impl rustc_ast_lowering::LoweringContext>::lower_expr_if
  14: rustc_data_structures::stack::ensure_sufficient_stack
  15: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
  16: <core::iter::adapters::flatten::Flatten<I> as core::iter::traits::iterator::Iterator>::next
  17: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
  18: rustc_arena::cold_path
  19: rustc_ast_lowering::LoweringContext::lower_block
  20: rustc_data_structures::stack::ensure_sufficient_stack
  21: rustc_ast_lowering::expr::<impl rustc_ast_lowering::LoweringContext>::lower_arm
  22: rustc_ast_lowering::Arena::alloc_from_iter
  23: rustc_data_structures::stack::ensure_sufficient_stack
  24: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
  25: <core::iter::adapters::flatten::Flatten<I> as core::iter::traits::iterator::Iterator>::next
  26: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
  27: rustc_arena::cold_path
  28: rustc_ast_lowering::expr::<impl rustc_ast_lowering::LoweringContext>::lower_expr_if
  29: rustc_data_structures::stack::ensure_sufficient_stack
  30: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
  31: <core::iter::adapters::flatten::Flatten<I> as core::iter::traits::iterator::Iterator>::next
  32: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
  33: rustc_arena::cold_path
  34: rustc_ast_lowering::expr::<impl rustc_ast_lowering::LoweringContext>::lower_expr_if_let
  35: rustc_data_structures::stack::ensure_sufficient_stack
  36: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
  37: <core::iter::adapters::flatten::Flatten<I> as core::iter::traits::iterator::Iterator>::next
  38: <smallvec::SmallVec<A> as core::iter::traits::collect::Extend<<A as smallvec::Array>::Item>>::extend
  39: rustc_arena::cold_path
  40: rustc_ast_lowering::item::<impl rustc_ast_lowering::LoweringContext>::lower_fn_body_block
  41: rustc_ast_lowering::item::<impl rustc_ast_lowering::LoweringContext>::lower_maybe_async_body
  42: rustc_ast_lowering::LoweringContext::with_hir_id_owner
  43: rustc_ast::visit::walk_item
  44: rustc_ast_lowering::item::<impl rustc_ast_lowering::LoweringContext>::with_parent_item_lifetime_defs
  45: <rustc_ast_lowering::item::ItemLowerer as rustc_ast::visit::Visitor>::visit_mod
  46: rustc_ast::visit::walk_item
  47: rustc_ast_lowering::item::<impl rustc_ast_lowering::LoweringContext>::with_parent_item_lifetime_defs
  48: <rustc_ast_lowering::item::ItemLowerer as rustc_ast::visit::Visitor>::visit_mod
  49: rustc_ast::visit::walk_item
  50: rustc_ast_lowering::item::<impl rustc_ast_lowering::LoweringContext>::with_parent_item_lifetime_defs
  51: <rustc_ast_lowering::item::ItemLowerer as rustc_ast::visit::Visitor>::visit_mod
  52: rustc_ast_lowering::lower_crate
  53: rustc_interface::passes::BoxedResolver::access::{{closure}}
  54: rustc_interface::passes::configure_and_expand::{{closure}}
  55: rustc_interface::passes::BoxedResolver::access
  56: rustc_interface::queries::Queries::lower_to_hir
  57: rustc_interface::queries::Queries::global_ctxt
  58: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  59: rustc_span::with_source_map
  60: rustc_interface::interface::create_compiler_and_run
  61: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: rustc 1.52.0-nightly (e9920ef77 2021-02-11) running on x86_64-unknown-linux-gnu
note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type lib
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
end of query stack
error: could not compile `project`
To learn more, run the command again with --verbose.
Process finished with exit code 101

Note:
A simpler program does not crash, but does not compile.
rust-lang/rfcs#2411 (comment)

#![feature(let_chains)]
use std::error::Error;
fn main(){
    let obj = Some(1);
    if let Some(i) = obj && i > 5 {

    }
}

error: `let` expressions are not supported here
 --> src/main.rs:5:8
  |
5 |     if let Some(i) = obj && i > 5 {
  |        ^^^^^^^^^^^^^^^^^
  |
  = note: only supported directly in conditions of `if`- and `while`-expressions
  = note: as well as when nested within `&&` and parenthesis in those conditions

#53667

[osa1]

Is it possible for you to share the code?

[HTGAzureX1212]

@qiujiangkun It might be better for you to share the code which reproduces the issue on your nightly, 2021-02-11, so that I can try to reproduce it on the latest nightly build and possibly find the commit that might have introduced this issue.

[JakkuSakura]

Okay, I'll trim down my base and share it later today.

[JakkuSakura]

I deleted my whole project and got this
lib.rs

#![feature(let_chains)]

pub struct Describer {}

impl Describer {
    fn process_input(&mut self) {
        let index = "1";
        if let Ok(index) = index.parse::<usize>() && index < self.l2_items.len() {
            self.select(index);
        }
    }
}

[osa1]

Thanks @qiujiangkun.

@rustbot label: -E-needs-mcve

[HTGAzureX1212]

Not sure if this helps: I ran bisect-rustc on my host target x86_64-pc-windows-msvc, and it is shown that it ICEd back in 2018 (even before the initial implementation of the let_chains feature.

[jyn514]

Duplicate of #82290.